Season the pork with Brazil spice mixture. Refrigerate for 1 day.
Heat a pan over medium-high heat and sear the pork on all sides until browned. Transfer to an ovenproof dish.
Add the mushroom juice and 1/8 liter of water to the dish. Place in a preheated oven at 175–200°C (350–400°F) and bake for 1.5 hours until the pork reaches an internal temperature of 63°C (145°F).
Remove from the oven and pour sour cream or sweet cream over the pork. Season the gravy with Brazil spice to taste and thicken if desired. Add the mushrooms.
Arrange the cheese slices over the roast. Return to the oven at 200°C (400°F) and bake for 10 minutes until the cheese is melted.